The project of nZEB school buildings: comparison among building technologies

An important part of the school building heritage in Italy is old. In fact, 55% of buildings were built before 1976 and are seriously inadequate both in relation to energy efficiency and other aspects such as seismic vulnerability and/or plant adaptation. 70% of the building stock consisting of school buildings was built for school intended use while the remaining 30% initially did not have this goal. The aforementioned data were made known by MIUR and give the idea of a complex and difficult management situation. The Law of 13 July 2015 n. 107 on the reform of the national education system establishes, inter alia, the construction of 60 innovative schools from an architectural, plant, technological, energy efficiency and structural and seismic safety point of view. Furthermore, with this Law, the Fund for the functioning of state schools is increased by € 123,9 million in 2016 and by € 126 million annually from 2017 to 2021. In this complex framework concerning the scholastic context, but attributable also to buildings with other intended use, the contribution of this work is inseted. This contribution does not want to deal with the relationship between educational innovation, design flexibility and technological innovation, even if in the proposal of the case study it inevitably refers to the guidelines for school buildings recently prepared by the ministry, but wants to contribute to deepen the exclusively technological aspect referring to the problem of the comparison and the most appropriate choice among construction technologies. In fact, this work, through the case study of the design of a school complex consisting of a nursery school, a kindergarten and an elementary school, located in the Municipality of Nove (VI), aims to compare three different technological systems with the same functional-spatial solution. The analysis takes into account and compares a plurality of aspects such as energy performance, in accordance with the requirements for nZeb buildings, costs and construction time. The study involves the comparison of dry and non-dry technologies. The orientation towards the use of one or other of the technological choices by the operators of the sector, represents a fundamental break for the different implications that the choice involves in relation to the construction process. In the first case the building system consists of a reinforced concrete frame and brick masonry, in the second case of a dry system with a steel structure and in the third of a dry system with a wooden structure in Cross Laminated Timber panels (CLT) and lamellar beams. The study highlights the different potentials and perspectives of these technologies with respect to the following three aspects: energy performances and emissions of CO2 in the atmosphere, costs and time of construction. Also due to the crisis that has hit the building sector in recent years, particular interest and attention are placed on the part of operators to develop and optimize the construction process; for this purpose costs and time of construction play a central role and both are decisive factors for the sustainable relaunch of the sector. The study aims to make a contribution to operators in that sector so that they can make more informed and profitable choices in relation to the use and application of the technologies taken into consideration, in accordance with the European and national guidelines for the sustainable renewal of the building heritage and in particular of school buildings one.